Known methods for analysing a material, in particular for the measurement of blood sugar are described in the following publications, for example:    Guo et al.: “Noninvasive glucose detection in human skin-using wavelength modulated differential laser photothermal radiometry”, Biomedical Optics Express, Vol, 3, 2012, No. 11,    Uemura et al.: “Non-invasive blood glucose measurement by Fourier transform infrared spectroscopic analysis through the mucous membrane of the lip: application of a chalcogenide optical fiber System”, Front Med Biol Eng. 1999; 9(2): 137-153,    Farahi et al.: “Pump probe photothermal spectroscopy using quantum cascade lasers”, J. Phys. D. Appl. Phys. 2012 and    M. Fujinami et al.: “Highly sensitive detection of molecules at the liquid/liquid interface using total internal reflection-optical beam deflection based on photothermal spectroscopy”, Rev. Sei. Instrum., Vol. 74, Number 1 (2003).    (1) von Lilienfeld-Toal, H. Weidenmüller, M. Xhelaj, A. Mäntele, W. A Novel Approach to Non-Invasive Glucose Measurement by Mid-Infrared Spectroscopy: The Combination of Quantum Cascade Lasers (QCL) and Photoacoustic Detection Vibrational Spectroscopy, 38:209-215, 2005.    (2) Pleitez, M. von Lilienfeld-Toal, H. Mäntele W. Infrared spectroscopic analysis of human interstitial fluid in vitro and in vivo using FT-IR spectroscopy and pulsed quantum cascade lasers (QCL): Establishing a new approach to non-invasive glucose measurement Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 85:61-65, 2012    (3) Pleitez, M. et al. In Vivo Noninvasive Monitoring of Glucose Concentration in Human Epidermis by Mid-Infrared Pulsed Photoacoustic Spectroscopy Analytical Chemistry, 85: 1013-1020, 2013    (4) Pleitez, M. Lieblein, T. Bauer, A. Hertzberg, 0. von Lilienfeld-Toal, H. Mäntele, W Windowless ultrasound photoacoustic cell for in vivo mid-IR spectroscopy of human epidermis: Low interference by changes of air pressure, temperature, and humidity caused by skin contact opens the possibility for a non-invasive monitoring of glucose in the interstitial fluid Review of Scientific Instruments 84, 2013    (5) M. A. Pleitez Rafael, 0. Hertzberg, A. Bauer, M. Seeger, T. Lieblein, H. von Lilienfeld-Toal, and W. Mäntele. Photo-thermal deflectometry enhanced by total internal reflection enables non-invasive glucose monitoring in human epidermis. The Analyst, November 2014.